Are Sub-National Agreements for Carbon Abatement Effective?

Although national commitments to the Paris Climate Accord have waned, carbon mitigation by sub-national entities is on the rise globally. We examine the effectiveness of sub-national jurisdictions (e.g., states, provinces, cities) in collectively enacting greenhouse gas abatement strategies. We develop a simple model to explore the conditions under which an agreement among sub-national jurisdictions within a country may lead to substantial carbon abatement relative to a national policy determined through majority rule. We find that, in the absence of a functional national policy response, a coordinated sub-national agreement can generate meaningful abatement. This could form an important stopgap measure in the absence of better alternatives.